The present invention pertains to models and devices used to train manual needle biopsy procedures. In particular, the present invention pertains to manual needle biopsy training methods and systems that use models of the human female breast. Breast cancer is among the most common malignant forms of cancer and is a leading cause of death from cancer among women in the United States. Various methods have evolved for breast examination and detection of early stage cancerous growths. Manual breast examination has been found to be a highly effective method of early breast cancer detection. Tactually accurate breast models have been developed to train the palpation techniques used in effective manual examination. Training success in breast palpation and self-examination is dependent in part on providing a realistic breast model that produces accurate tactile responses in the user. For this reason, breast models have been designed with lifelike texture and tactile properties.
Lumps or other breast tissue abnormalities revealed by clinical examination or other physical examination methods may be indicators of any of a variety of conditions, some of which are benign and relatively inconsequential to health. A first step in investigating tissue abnormalities is most often a needle biopsy. In needle biopsy, the breast is typically first palpated to locate the subject lump. A needle attached to a syringe or a similar suction device is then passed through the breast until penetrating the lump. A portion of the suspected tissue is then aspirated and withdrawn for testing. Successful needle biopsy requires training to assure quick and accurate location of the lump and certain penetration of the lump by the aspiration needle. Lengthy probing potentially exposes the patient to trauma and inaccuracy may result in false negative test results for failure to aspirate the correct tissue. Traditionally, needle biopsy techniques are taught in medical schools using actual patients. This situation is problematic in view of the majority of patients"" unwillingness to cooperate in such training procedures. Consequently, breast models similar to those used for breast self-examination have been developed for training needle biopsy. One such device is provided in U.S. Pat. No. 5,803,746 to Barrie et al.
Because in the clinical situation, the target of a free-hand needle biopsy is an invisible lesion that must be located by palpation, training devices preferably similarly prevent the trainee from viewing the target lump. However, this inevitably results in an inefficient trial-and-error methodology in practice. The Barrie device suffers from this weakness. Breast examination can be improved if a trained instructor is able to view the trainee""s needle and the target within the breast model to provide instant comment and corrective feedback on a trainee""s technique. However, prior breast models do not provide a means that enables an instructor to view a trainee""s technique while blocking trainee visual access to the model. The same elements obscuring the trainee""s vision also obscure the instructor""s. Various imaging systems for visualizing biopsy needles and phantom lumps within breast models based on such methods as ultrasound and X-ray have been suggested. Examples of these are provided in U.S. Pat. No. 4,493,653 to Robbins et al. and U.S. Pat. No. 5,273,435 to Jacobson. However, the construction of the breast models in these systems preclude proper palpation technique and are very cumbersome. In addition, the viewing operations of these prior methods interfere with training activities. Effective palpation in needle biopsy training demands the same lifelike properties in a training model designed to teach the skill of manual breast examination. However, existing self-examination breast models suffer from the same defect as the Barrie devices. For example, U.S. Pat. No. 4,134,218, to Adams et al. and U.S. 4,867,686 to Goldstein disclose models of a human female breast having lifelike texture and tactile response to palpation. These references also teach various methods of palpation training including providing transparent breast elements to allow the trainee to observe the subject lumps after palpation to verify technique. However, neither Adams nor Goldstein provide a device or method enabling a secondary viewer such as an instructor to view a trainee""s palpation technique at the time the trainee is palpating the model.
What is needed is a lifelike breast model including lumps simulating various anomalous tissues and providing an optical path that enables a second viewer such as an instructor to observe a trainee""s needling technique while enabling obscuring the trainee""s view of the target tissue.
The present invention is a training aid for teaching needle biopsy of the human breast. It provides breast models having lifelike properties providing accurate tactile sensation during palpation of the breast that enable a trainee to learn to locate internal lesions and similar anomalous tissues in the breast. These same properties also allow trainee learning of tactile sensations that indicate relative position and motion of biopsy needles during biopsy needling procedures. To facilitate tactile learning, one breast model of the invention includes an opaque skin that blocks the trainee view of a breast cavity containing simulated lesions, ensuring that needling procedures are performed based solely on xe2x80x9cfeelxe2x80x9d. Such xe2x80x9cblindedxe2x80x9d breast models are supported in a position to allow access to the surfaces normally palpated and penetrated during clinical needling procedures, while allowing viewing of the breast internal elements by a second party such as an instructor. In one embodiment, the breast model is supported on a transparent surface of a portable stand. The stand includes optical elements creating a viewing path from the breast cavity to a second location separate from the trainee. In this way, a trainee may practice needling based solely on simulated tactile information while an instructor observes internal events, enabling real-time comment and instruction. Because viewing is accomplished by optical light pathways and not penetrating electromagnetic radiation (x-ray) or other penetrating energy (ultrasound), potential interference of trainee activities by the viewing operations is eliminated. The models and stands and methods provided allow for palpation and needling of the entire breast model surface and volume without moving the model and while providing continuous viewing by second persons. The present invention includes training systems incorporating breast models and viewing stands and methods of training incorporating these structural aids.
The present invention also includes training methods using an alternative breast model that is sufficiently transparent to allow direct viewing of modeled lesions from any relative position. In preferred training methods of the invention, this model is used to provide xe2x80x9cerror-freexe2x80x9d training in which a trainee learns proper tactile indicators of accurate needling techniques. This training mode may be used independent of, or more preferably, preliminary to, training with xe2x80x9cblindedxe2x80x9d models. The present invention includes training systems including blinded and transparent models and methods of training incorporating both. The present devices and methods of presenting and viewing breast models are also used in methods of teaching examination of breast tissues by palpation without needling.
Particular benefits of the invention include small portable and unpowered embodiments that are easily and cheaply employed in a variety of circumstances. Other advantages of the invention as described in the following drawings, detailed description, and claims will apparent to one skilled in the art.